1. Field Of The Invention
This invention relates, in general, to fluid control valves and, more specifically, to pressure converter valves.
2. Description Of The Prior Art
Fluid flow control valves find wide spread use in industry to control the movement of fluid operated devices such as cylinders and motors. Such valves are connected via piping to a source of high pressure fluid, such as a hydraulic pump, and to a return tank or reservoir such that fluid flows under high pressure through the valves from the source to the cylinders or motors causing the desired movement thereof and returns under low pressure from the cylinders through the valves to the tank.
These valves are typically connected in a group on a manifold arrangement to the source and return tank and provide at their output ports fluid under high pressure from the source and fluid under low pressure returning to the tank.
It is often necessary to add additional valves to an existing machine in order to provide additional movement or desired operations on the machine. However, this has presented several problems utilizing prior art control valves since the piping to the cylinders, which must be tapped or broken into in order to add the extra valve, alternately switches between high and low pressure. This makes the operation of the additional device dependent upon the direction of fluid flow through the preceding valve, which is unworkable.
As shown in U.S. Pat. No. 3,256,908, it has been proposed to provide a plurality of unidirectional flow devices or check valves to assure that a first fluid flow path is a source of fluid to the device and a second fluid flow path receives fluid from the device without regard for the direction of fluid flow in the valves preceding the device. Although this arrangement functions satisfactorily, the use of individual check valves requires considerable time and expense for installation and consumes space that is often not available on a complex machine tool.
Thus, it would be desirable to provide a pressure converter valve which overcomes the problems of prior art attempts to provide fluid flow paths that provide the same fluid flow pressure regardless of the direction of fluid flow input to the converter valve. It would also be desirable to provide a pressure converter valve arrangement which is simple and easy to install and requires a minimum amount of space. It would also be desirable to provide a pressure converter valve arrangement which is suitable for use with conventional, standardized fluid flow control valves. Finally, it would be desirable to provide means for mounting an auxiliary valve and fluid operated device in fluid communication with the pressure converter valve without the use of additional piping.